You have conflated Gods Holy law with the temporal ceremonial laws which were to point to and remind them of the coming Messiah. The Ten Commandments were permanent. They were wrote in stone by Gods Finger. They were instituted at Creation. Re-instituted at Mt. Sinai. Lived out in the life of Jesus Christ on earth. Jesus kept the Sabbath in life and death. He is Lord of the Sabbath. He came not to destroy the Law but to fulfill it. Not one jot or tittle will be changed until earth and Heaven passes away and that has not happened. So it is still in force.
The Saturday Sabbath is as much a part of the New Law as circumcision, keeping kosher, and not mixing fibers in garments. I have no issue with Christians who are of Jewish heritage keeping those things as a remembrance, but they were never required of Gentile Christians. If you think otherwise, you need to re-read Galatians.